NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 107 



are badly broken and the uppermost arm spine is missing from most 

 of the remaining joints. Perhaps this is due to the character of the 

 bottom from which they were dredged. 



OPHIOMUSIUM LUTKENI. 



Ophiomusium liitkeni LYMAN, Bull. Mus. Comp. Zool., vol. 5, 1878, p. 114. 



Localities. Albatross station 4900, Eastern Sea, lat. 32 28 / 50' / N.; 

 long. 128 34' 40" E., 139 fathoms, gray sand, broken shells, bottom 

 temperature 52.9, 5 specimens; station 4933, Eastern Sea, lat. 30 

 59' N.; long. 130 29' 50" E., 152 fathoms, rocky, bottom temperature 

 56, 3 specimens. Bathymetrical range, 139 to 152 fathoms. Tem- 

 perature range, 56 to 52.9. Eight specimens. 



I have compared these specimens with a cotype of luikeni and 

 although there -are slight differences, I think it safe to call them that 

 species. In the luikeni from Challenger station 192 (off Kei Islands, 

 Arafura Sea), many grains of sand and shells of foraminifera still 

 remain attached to the specimens, and the whole surface of disk and 

 arms is pitted as though by the pressure of similar bodies when the 

 epidermal covering was soft. I am unable to decide whether this 

 appearance is natural or artificial, but at any rate the Japanese 

 specimens are not so pitted. In the latter, too, the arm spines are 

 longer and the arm-plates a little more swollen, but these differences 

 are slight and variable. The Albatross specimens have the disk 10 to 

 13 mm. in diameter and are light brown in color. 



OPHIOMUSIUM LUNARE. 



Ophiomusium lunare LYMAN, Bull. Mus. Comp. Zool., vol. 5, 1878, p. 116. 



Locality. Albatross station 4934, Eastern Sea, lat. 30 58' 30" N.; 

 long. 130 32' E., 103 to 152 fathoms, rocky, bottom temperature, 

 60.6 to 56, 7 specimens. 



The disk diameter of these specimens ranges from 6 to 13 mm.; 

 they are thus larger than the Challenger specimen, but none of them 

 is so large as the largest taken by the Siboga. The species is remark- 

 ably well characterized and correspondingly easy to recognize. 

 There is very little difference in appearance between the smallest 

 and largest specimens, even in the number and arrangement of the 

 disk scales; only in the larger specimens, the basal side arm plates 

 carry some minute scattered spinelets above the regulation pair. 



OPHIOMUSIUM LYMANI. 



Ophiomusium lymani WYVILLE THOMSON, The Depths of the Sea, 1873, p. 172. 



Localities. Albatross station 3074, off Washington, lat. 47 22' N.; 

 long. 125 48' 30" W., 877 fathoms, green mud, bottom temperature 

 36.6, 29 specimens; station 3075, off Washington, lat. 47 22' N.; 

 125 41' W., 859 fathoms, green mud, bottom temperature 36.6, 



